This study utilizes over 200 patients. These are selected from the files of our laboratory on the basis of a) presence of EEG epileptiform activity localized within one or both temporal regions; b) availability of reliable and detailed repeated observations and description of seizure episodes. This project is expected to yield data which may throw some light on the pathophysiology of temporal lobe seizures. From a practical viewpoint the study should provide useful information for a more accurate localization of the epileptogenic process and a better selection of candidates for surgical treatment.